CD-adapco, the largest privately held CFD-focused provider of Computer Aided Engineering software, has released the release 10.04.011-R8 (double precision) of STAR-CCM+ its the latest version of its flagship simulation tool, of new Colormaps and Customization.

STAR-CCM+ 10.04 Preview : New Colormaps and Customization

We know a good scientific visualization when we see one - colormaps are a big part of this and when used effectively, they can make all the difference. The ability to create your own colormap within STAR-CCM+ has been around for a long time and around this time last year, we delivered a full featured interactive colormap editor with the 9.04 release.

If this is news to you, guess what : Rogowitz & Treinish1 were calling attention to the shortcomings of the rainbow colormap twenty years ago. Since then, several well considered, provocatively titled articles like "How the Rainbow Color Map Misleads" , "Rainbow Color Map (Still) Considered Harmful" and even "Dear NASA: No more Rainbow Color Scales, Please" have further exposed the limitations of the rainbow colormap.

So, now that we know the rainbow colormap shouldn't be our first choice, what alternatives do we have?

Drawing from very well considered colormap requirements summarized by Moreland5, we've put together 22 new colormaps and added them into 10.04, ready to use. These new colormaps can be grouped into four categories: High-Impact, Perceptual, Diverging and Specialty.

One of the primary concerns for many of us, and equally to authors in this area of research, is that colormaps should be visually pleasing. We've balanced contradictory color selection best practices against aesthetics, delivering several High-Impact colormaps that are minimally distorted by lighting and are well suited to a wide range of applications. The Perceptual green-mauve, orchid-green, tropical and water colormaps are the easiest to interpret and are of particular benefit to individuals with color blindness such as deuteranopia, protanopia or tritanopia. Diverging colormaps highlight either large differences (purple-red & purple-red basic) with an unsaturated color at the center position of the colormap, or small differences (red-blue & red green) with nearly unsaturated colors placed at the ends of the colormap. Lastly, Specialty maps like the land elevation, land-sea elevation, casting and thermal ramps are designed for specific applications. We anticipate that these new colormaps will streamline your workflows by removing the need to create custom colormaps of your own. And, we've made it possible for you to specify your own default colormap through our Tools > Options > Visualization settings for everyday use.

The next topic for today: Customization. As you gain familiarity with STAR-CCM+, it's likely that you've authored a java macro (or two) to save you time on daily, routine, specialized tasks. But as new projects come in, it's easy to forget "where" these various java macros are and "what" they actually do. Even if your scripting efforts are well organized, you still need to be able to find and play these "time-savers". With v10.04, you will be able to run any one from up to 10 java macros, directly from any toolbar. You can even specify an icon and a hover tooltip to remind you what your macro does.

The first (which you can download from here) cycles through all of the candidate colormaps for a chosen scalar displayer, saving an image for each colormap to a specified folder. This lets us make comparisons between many colormaps we had under consideration and substantially streamlined our efforts to arrive at the final 22 colormaps that we've included.

The second macro (which you can download from here) was created to provide enhanced flexibility for diverging colormaps. Our diverging maps, associate a critical scalar value with the center position of the colormap. To correctly visualize +/- differences, the scalar minimum and maximum extents need to be equidistant from a median scalar value. To see how this can be used in practice, lets look at the radial velocity component in the vicinity of a mixing impeller. In the leftmost illustration of the sequence below, a divergent map effectively shows where fluid is being pushed outward (in red) away from the shaft, or inward (in blue) towards the shaft. And the scalar minimum and maximum extents (+/- 0.80) are set equidistant from the critical radial velocity component (equal to 0). However, variations in the negative radial velocity are difficult to see. In the center illustration, we've changed the minimum extent to pick up more detail, but, the white color in the middle of colorbar is no longer associated with the critical radial component - the larger blue region incorrectly implies that there is more fluid moving toward the impeller shaft than there really is. To fix this, we run the the second macro, right from our toolbar, which shifts all the control points in the colormap to account for the offset of the critical radial component using the modified scalar extents (-0.40 to +0.80). Once again our critical scalar lines up with the neutral white color. The end result at right shows enhanced detail for the variation of the radial velocity component.

With every STAR-CCM+ release, we pay close attention to all aspects of your productivity. The newly added colormaps should help you to quickly create high impact and effective scientific visualizations of your results and you can certainly use them as a starting point. I'm not sure how big a hint I am allowed to drop, but my suggestion is that if you want to win the 2016 Calendar Contest (open now) you should investigate using alternative colormaps in your submission. Finally, we need to appreciate that a java macro can be capable of saving us a tremendous amount of time with a little investment up front. Making your macros accessible has been a long standing feature request that we are pleased to be able to deliver this time around.